Proton Pump Inhibitors: The Culprit for Barrett's Esophagus?

Lactobacillus sp. Facilitate the Repair of DNA Damage Caused by Bile-Induced Reactive Oxygen Species in Experimental Models of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) leads to the accumulation of bile-induced reactive oxygen species and oxidative stress in esophageal tissues, causing inflammation and DNA damage. The progression sequence from healthy esophagus to GERD and eventually cancer is associated with a microbiome shift. Lactobacillus species are commensal organisms known for their probiotic and antioxidant characteristics in the healthy esophagus. This prompted us to investigate how Lactobacilli survive in a bile-rich environment during GERD, and to identify their interaction with the bile-injured esophageal cells. To model human reflux conditions, we exposed three Lactobacillus species (L. acidophilus, L. plantarum, and L. fermentum) to bile. All species were tolerant to bile possibly enabling them to colonize the esophageal epithelium under GERD conditions. Next, we assessed the antioxidant potential of Lactobacilli and role in bile injury repair: we measured bile-induced DNA damage using the ROS marker 8-oxo guanine and COMET assay. Lactobacillus addition after bile injury accelerated repair of bile-induced DNA damage through recruitment of pH2AX/RAD51 and reduced NFκB-associated inflammation in esophageal cells. This study demonstrated anti-genotoxic and anti-inflammatory effects of Lactobacilli, making them of significant interest in the prevention of Barrett's esophagus and esophageal adenocarcinoma in patients with GERD.

Effects of proton pump inhibitor use on the esophageal microbial community

BACKGROUND

Changes in the esophageal microbiome correlate with esophageal disease, but the effects of proton pump inhibitor (PPI) drugs are incompletely characterized. Our objective was to identify the effects of PPI use on the microbial community of the esophagus.

METHODS

Mucosal biopsies of the distal esophagus were analyzed using a customized esophageal microbiome qPCR panel array (EMB). Patient demographics, use of PPIs, duration of use and dose were recorded.

RESULTS

Fifty-eight patients were included. Mean age was 60.5 years. Ninety percent (52/58) of patients were on PPIs. Mean dose was 42.7 mg. Mean duration of use was 2.5 years. The use of PPIs led to a significant difference in absolute levels of only one organism, Actinomyces, in the entire array (p < 0.01). Among patients who used proton pump inhibitors, there was no significant association between dose and absolute levels of any organism. Similarly, there was no association between duration of use and absolute levels of any organism.

CONCLUSIONS

PPI use does not seem to cause significant changes in the distal esophageal microbial community. Future studies with larger sample sizes and esophageal pH testing should be performed to determine the level of acidity and its relationship to the microbial community.

Long-term Proton Pump Inhibitor Administration Caused Physiological and Microbiota Changes in Rats

Proton pump inhibitors (PPIs) are used for the long-term treatment of gastroesophageal disorders and the non-prescription medicines for acid reflux. However, there is growing concerns about PPI misuse, overuse and abuse. This study aimed to develop an animal model to examine the effects of long-term use of PPI in vivo. Twenty one Wistar rats were given omeprazole orally or intravenously for 30 days, and caerulein as a positive control. After euthanization, the serum and stool were collected to perform MS-based quantitative analysis of metabolites. We carried out 16S-based profiling of fecal microbiota, assessed the expression of bile acid metabolism regulators and examined the immunopathological characteristics of bile ducts. After long-term PPI exposure, the fecal microbial profile was altered and showed similarity to those observed in high-fat diet studies. The concentrations of several metabolites were also changed in various specimens. Surprisingly, morphological changes were observed in the bile duct, including ductal epithelial proliferation, micropapillary growth of biliary epithelium, focal bile duct stricture formation and bile duct obstruction. These are characteristics of precancerous lesions of bile duct. FXR and RXRα expressions were significantly reduced, which were similar to that observed in cholangiocarcinoma in TCGA and Oncomine databases. We established a novel animal model to examine the effects of long-term use of omeprazole. The gut microbes and metabolic change are consequences of long-term PPI exposure. And the results showed the environment in vivo tends to a high-fat diet. More importantly, we observed biliary epithelial hyperplasia, which is an indicator of a high-fat diet.

Proton Pump Inhibitors and Radiofrequency Ablation for Treatment of Barrett's Esophagus

Gastroesophageal Reflux Disease (GERD) is characterized by acid and bile reflux in the distal oesophagus, and this may cause the development of reflux esophagitis and Barrett's oesophagus (BE). The natural histological course of untreated BE is non-dysplastic or benign BE (ND), then lowgrade (LGD) and High-Grade Dysplastic (HGD) BE, with the expected increase in malignancy transfer to oesophagal adenocarcinoma (EAC). The gold standard for BE diagnostics involves high-resolution white-light endoscopy, followed by uniform endoscopy findings description (Prague classification) with biopsy performance according to Seattle protocol. The medical treatment of GERD and BE includes the use of proton pump inhibitors (PPIs) regarding symptoms control. It is noteworthy that long-term use of PPIs increases gastrin level, which can contribute to transfer from BE to EAC, as a result of its effects on the proliferation of BE epithelium. Endoscopy treatment includes a wide range of resection and ablative techniques, such as radio-frequency ablation (RFA), often concomitantly used in everyday endoscopy practice (multimodal therapy). RFA promotes mucosal necrosis of treated oesophagal region via high-frequency energy. Laparoscopic surgery, partial or total fundoplication, is reserved for PPIs and endoscopy indolent patients or in those with progressive disease. This review aims to explain distinct effects of PPIs and RFA modalities, illuminate certain aspects of molecular mechanisms involved, as well as the effects of their concomitant use regarding the treatment of BE and prevention of its transfer to EAC.

Maintenance use of non-steroidal anti-inflammatory drugs and risk of gastrointestinal cancer in a nationwide population-based cohort study in Sweden

OBJECTIVES

Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) are potential candidates for chemoprevention of gastrointestinal cancer. We aimed to assess the association between contemporary NSAID use (≥180 days) and gastrointestinal cancer.

DESIGN

Nationwide Swedish population-based cohort study (2005-2012).

SETTING

Sweden PARTICIPANTS: All adults exposed to maintenance NSAIDs use (aspirin, n=783 870; unselective NSAIDs, n=566 209, selective cyclo-oxygenase (COX)-2 inhibitors, n=17 948) compared with the Swedish background population of the same age, sex and calendar period.

OUTCOME MEASURES

The risk of different gastrointestinal cancer types expressed as standardised incidence ratios (SIR) and 95% CIs, taking into account concurrent proton pump inhibitors (PPIs) and statins usage.

RESULTS

The SIR for gastrointestinal cancer for aspirin use was 1.02 (95% CI 1.00 to 1.04), with clearly reduced risk for long-term users (SIR=0.31, 95% CI 0.30 to 0.33 for 5.5-7.7 years), but an increased risk for short-term users (SIR=2.77, 95% CI 2.69 to 2.85), and stronger protective effect for low-dose aspirin (SIR=0.86, 95% CI 0.85 to 0.88). Users of non-selective NSAIDs showed an overall decreased risk of gastrointestinal cancer (SIR=0.79, 95% CI 0.77 to 0.82), in particular for cancer of the stomach, colorectum and oesophagus, and the SIRs were further decreased among long-term users. Users of selective COX-2 inhibitors showed a SIR=0.89 (95% CI 0.73 to 1.09) for gastrointestinal cancers. Both aspirin and unselective NSAIDs users who also were using PPIs, had higher risks for all gastrointestinal cancer types; and lower risk if using statins.

CONCLUSION

Long-term use of (low-dose) aspirin and non-selective NSAIDs was associated with a decreased risk of all gastrointestinal cancer types.

Proton Pump Inhibitors Do Not Reduce the Risk of Esophageal Adenocarcinoma in Patients with Barrett's Esophagus: A Systematic Review and Meta-Analysis

Objectives

Proton pump inhibitors (PPIs) have been used for treatment of Barrett's esophagus (BE) for many years. However, the connection between PPIs and esophageal adenocarcinoma (EAC) in patients with BE has still been controversial. The current systematic review and meta-analysis was designed to evaluate the association between PPIs and the risk of EAC or high-grade dysplasia (HGD) in patients with BE.

Methods

A systematic literature search of studies reporting the association between PPIs and the risk of EAC and/or HGD in patients with BE was conducted in PubMed, Embase, Web of Science and the Cochrane Library. Next, literature was screened using previously established criteria and relevant data were extracted from included studies. Finally, the software program Review Manage 5.2 was applied to aggregate data and analyze the results.

Results

Nine observational studies, comprising five cohort and four case-control studies (including a total of 5712 patients with BE), were identified. Upon meta-analysis, PPIs were found to have no association with the risk of EAC and/or HGD in patients with BE (unadjusted OR 0.43, 95% CI 0.17–1.08). Analysis for duration response relationship revealed no significant trend toward protection against EAC or HGD with PPIs usage for >2~3 years (one study using 7-year cutoff) when compared to usage for shorter time periods (PPIs usage >2~3 years vs. <2~3 years: OR 0.91 (95% CI 0.25–3.31) vs. 0.91 (0.40–2.07)).There also was considerable heterogeneity between studies.

Conclusion

No dysplasia- or cancer-protective effects of PPIs usage in patients with BE were identified by our analysis. Therefore, we conclude that clinicians who discuss the potential chemopreventive effects of PPIs with their patients, should be aware that such an effect, if exists, has not been proven with statistical significance.

Esophageal cancer: The latest on chemoprevention and state of the art therapies

Esophageal cancer is currently the 8th most common cancer worldwide and the 6th leading cause of cancer-related mortality. Despite remarkable advances, the mortality for those suffering from esophageal cancer remains high, with 5-year survival rates of less than 20%. In part, because most patients present with late-stage disease, long-term survival even after resection and therapy is disappointingly low. As we will discuss in this review, multiple characteristics specific to the disease stage and patient must be considered when choosing a treatment plan. This article will summarize current standard therapies, potential application of chemoprevention drugs and the promise and partial failure of personalized medicine, as well as novel treatments addressing this disease.